1. Field
Apparatuses consistent with exemplary embodiments generally relate to a backlight unit and a display apparatus employing the same.
2. Description of the Related Art
A general reconfigurable backlight unit used to produce local dimming includes a two-dimensional (2D) array of light-emitting diodes (LEDs), and a diffuse sheet. The general reconfigurable backlight unit may be controlled by individually driving the LEDs. A backlight unit of a liquid crystal display apparatus for performing local dimming should generate an accurately controllable light pattern for backlighting a liquid crystal panel when a high-contrast image is displayed, and should provide uniform illumination for a low-contrast image. However, since an area of an image panel of the liquid crystal display apparatus, which is illuminated by each LED, overlaps an area corresponding to another LED, accurate control of the backlight unit is not easy.
Also, a reconfigurable backlight unit acts as a generator of vertical or inclined light stripes to provide selective visions of different views displayed on a liquid crystal display panel by alternating columns, and may be employed in a 2D/three-dimensional (3D) switchable autostereoscopic display apparatus.
A general backlight unit may include an array of sets of red (R), green (G), and blue (B) LEDS aligned at equal intervals on a backlight unit covered by a diffuser.
Due to high cost, the number of LEDs in a backlight unit is not generally large and thus each LED is mounted together with an optical lens having a shape for spreading light emitted from the LED to a wide area on the diffuser. In order to provide uniform illumination, footprints of light beams generated by different LEDs overlap each other. As a result, a pattern generated by the backlight is reduced in resolution and thus is blurred. The blur requires additional image processing to be performed in a display apparatus for realizing local dimming.